Elastic strand for elastic fabrics



s. c; LILLEY 2,262,017 I ELASTIC STRAND FOR ELASTIC FABRICS Nov. l1, 1941.

Filed Nov; 28. 1940 2% Patented Nov. ll, 1941 UNITED STATES PATENTl OFFICE 2,262,017 ELASTIC STRAND FOR ELASTIC FABRICS Samuel C. Lilley, Hamden, Conn., assignor, by

mesne assignments, to United Elastic Corporation, Easthampton, Mass., a corporation of Massachusetts Application November 2s, 1940, serial No.l 367,491

2 Claims. (Cl. 575-149) The present inventionrelates to improvements in elastic strands for elastic fabrics and constitutes an improvement upon the elastic strands `disclosed in my U. S. Patents Nos. 2,146,965 and 2,146,966, both dated February 14, 1939.

One of the objects of the present invention is to provide a superior elastic strand for incorporation into elastic fabrics, which strand is provided with a superior coating combining heatactivatable properties with the property of protecting the elastic strand proper from the deleterious effects orV air, perspiration, and other skin excretions.

Another object of the present invention is to provide a superior elastic strand for incorporation into elastic fabrics with a coating which will not only discharge the function of adhering covering material to the, strand-body, but will, at the same time, shield the saidv elastic strandbody from the deleterious effects of ultra-violet light and chemically-active washing compounds. A further object of the present invention yis to provide a superior elastic strand having a coating of heat-activatable thermo-plastic material capable of securely adhering covering material to the elastic strand proper and at the same time possessing an elasticity approximating the elasticity of the said strand proper, to

thereby avoid a rupture between the stran body proper and the coating material.

With the above and other lobjects inview, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel w. over the prior art.

' coating of polymerized iso-butylene;

Fig. 3 is a view in` end elevation of the struc' ture of Fig. 2;

Fig. 4 is a broken view in side elevation showing the elastic strand-body partly coatedA with polymerized iso-butylene and having a helical wrapping applied thereto;

Fig. 5 is an end view of the structure of Fig. 4;. Fig. 6 is a view corresponding to Fig. 4 but y showing the addition thereto of an outer'helical wrapping of textile material; i

Fig. 'list an end view of the structure of Fig. 6; Fig. 8 is a broken longitudinalsectional view taken on the line 8-8 of Fig. 6, but on a larger i scale; and

Fig. 9 is a broken forming coating of polymerized iso-butylene has been activated by heat toadhere the inner layer of covering strands to the elastic strand-body.-

As will be apparent from the following, the present invention contemplates the employment ofan elastic'strand-body having a coating of thermo-plastic adhesive-forming material com-- pcsel primarily of polymerized iso-butylene which possesses special advantages when com'- binedgas a covering upon strand-bodies of rubber-base material. K

In carrying out the present invention, an elastic strand-body Ill'is employed which in the particular. instance shown is of circular form inv cross section, though the cross sectional form may be rectangular or of other suitable cross section, a's is well known in the art..

yThe elastic strand-body I0 above referred to may be made of a wide variety of elastic mateyrials such as vulcanized rubber compounds common in the textile art and preferably having a heat-disintegrating point at' a temperature materially above the temperature at which the hereinafter-referred-to thermo-plastic adhesiveforming material will effectively soften. Specific examples of elastic materials from which the strand-body I0 or itsequvalent may be formed are so numerous and well known in the art as not to require detailed description herein, save to note that as in the case of practically all rubber-base compounds, -the material is subject to oxidation and the disitegrating effects of ultraviolet light, etc.

Around the perimeter of the elastic strandbody I I) is applied a coating Il of thermo-plastic adhesive-forming material formed mainly or entirely of polymerized iso-butylene whichis a saturated member of the group which may be designated as aliphatic iso-olefin polymers;

By way of example, the following may be'eni' ployed as the thermo-plastic adhesive-forming Vmaterial in conjunction with the rubber-base elastic strand-bodies.

Example A Polymerized iso-butylene dissolved in naphtha,

toluol, or other suitable solvents, which may be driven off by mild heat, following the completion view substantially .corresponding to Fig. 8, but showing the covered 1 strand after the. substantially-dry adhesive.

of the application of the polymerized iso-butylene to the strand-body.

Example B Polymerized iso-butylene dispersed in water with or without clay, casein, or other suitable dispersing aids.

Example C Per cent Polymerized iso-butylene 9'?y Rosin 3 Both of the above dissolved-or dispersed in either naphtha or its equivalent,l or in an aqueous solution.

Example D Per cent Polymerized iso-butylene -.-i 'Z8 Carbon black i--- 22 The above may be dissolved or dispersed in vnaphtha or its equivalent, or in an aqueous dispersion.

The coating II of polymerized iso-butylene r'nay be applied to the strand-body III in any suitable manner such, for instance, asby im- I in the form of the coating H orjits equivalent by depositing .onv the said strand-body an aqueous dispersion or emulsion of the polymerized iso-butylene. Such aqueous dispersion or emulsion is particularly advantageous inasmuch as its .use in processing involves no fire hazard. If desired, however, and as before noted, the polyf merized iso-butylene may be dispersed in a suitable' solvent such as naphtha.

After the strand-body' III has had the coating II or its equivalent applied to it and after the said coating has been dried to a nonliquid condition, a layer of textile covering material I2 may beapplied directly over the thermo-plastic adhesive-forming coating IIf as is cially well in Figs. 4 and 5.

Should it be found desirable and in order to insure the ready handling of the catedstrands of Figs. 2 and 3 and after the same have been substantially dried, the said strand may be treated with talc. or other' adhesiveness-reducing material such, for instance, as those described in my prior Patent No. 2,146,966. In this manner and under conditions where necessary, the coated strands may be rendered convenient for passing through covering machines, looms, etc., though in most instances the coating I I may be rendered suiiiciently non-tacky by mild heating.

shown espe- When the elastic strand-body I0 with its thermoplastic adhesive-formingk coating Il is subjected to heat in commotion with covering material, such as I2, or the crossing strands of an elastic fabric, the said coating II will soften or melt to a sumcient degree to secure a rm grip upon the covering material and firmly anchor the same to the strand-body I0. An exposure of the coating II to a temperature of aboutv2l5 F. for a period of ve `minutes is usually adequate to secure the necessary bonding. This time and temperature are substantially those employed in finishing elastic fabrics on so-called dry can flnishing machines. Lesser heats may be employed over longer periods of time or higher degrees of heat over much briefer periods of time.- Within reasonable 11mits, neither the time nor temperatures are critical.

The heating of the coating of polymerized iso-butylene such as I-I to secure the adhesive properties referred to, may be accomplished before or after the coated strand such as is shown in Figs. 2 and 3," is incorporated into a woven, knitted or netted fabric, either with or without the coverings I2 or I3. In some instances, however, it is preferred to adhere covering material,

such as I2, to the strand-body prior to the samel beingy incorporated in a fabric and this may be readily accomplished by passing the coated -strand with its covering material through a heated chamber, to thus secure continuous straight-line production. i

When the coating II or its equivalent composed primarily of polymerlzed iso-butylene is subjected to heat in .conjunction with suitable covering material, such as I2, or the crossing strands in a fabric, not only is the strand-body f I0 firmly united to the selected covering material but the polymerlzed iso-butylene coating remains as a protective coating minimizing or substantially eliminating the oxidizing of the rubberbase strand-body I0 or its equivalent and protecting the same also Vagainst the deleterious effects of ultraviolet light and of perspiration and other skin excretions, washing compounds, etc.

The strands of the character and in the conchemically-active dition especially well shown in Figs. 2 and 3, may

If desired and as is shown especially well in Figs.'6 and 7, a second layer Ilsof covering material may be'wrapped over .the previously described layer I2 when especially severe specifi The coating u of pmymerized iso-bumenis' usually suiliciently soft to permit the convolutions of the covering material I2 to slightly press into the said coating when the` said covering material is applied under tension, as is indicatedl in Fig. 8.

-be conveniently stored, shipped and sold at normal temperatures without causing objectionable adhesions` between various parts of a strandor of various adjacent strands 'and still retain their ability to become adhered to a covering material when subjected to suitable degree of heat.

Under other conditions, the elastic strands of the present invention may be marketed with adhered covering material such as I2, instead of being marketed. in the substantially naked conditions with merely the coating II applied thereto and rendered non'liquid.

The elastic an'd coated strands of. the present invention, like those of my prior patents herein referred to, possess the characteristics of being conveniently adhered to any suitable covering material and,- in addition the coating of polymerized iso-butylene serves to an exceptional degreeito protect the rubber-base strand-,body from the deleterious effects of oxygen, perspiration ultravioletdight, etc.

specific ways than these herein set forth without departing from the spirit and essential characteristics of the invention, and the presentv embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

The invention may be' carried out in other I forming material and all changes coming within-the meaning and equivalency range of the appended claims are intended to be embraced therein. A

I claim:

1. A new article of manufacture, an elastic strand adapted to be woven or knitted into elastic fabrics and to be adhered to textile covering material by heat, and comprising: an elastic strand-body of rubber-base material having its exterior provided with a nonliquid heat-activatable thermo-plastic adhesive-forming material containing over fty per cent of polymerized iisobutylene and adapted to thermo-plastically adhere the said strand body to textile covering material when heated in conjunction therewith; the said rubber-base strand-body forming the major portion of the cross-sectional area of the strand and the said adhesive-forming material forming a. minor portion of the said cross-sectional area thereof and acting as a protective coating for the said strand-body, whereby the said adhesiveserves to shield and protect the said strand-body from the deleterious eiects of ultraviolet light and other harmful exterior media.

2. A covered elastic strand of the type adapted to be woven or knitted into elastic fabrics and comprising: an elastic strand-body of oxldizable material; textile covering material extending around the said strand-body; and an adhesive SAMUEL C. LILLEY. 

